Patent EP-2090921-A1 (EP)
Inventor: ANGER WILHELM
IPC: G02C5/00
Filed: 2008-02-18
Abstract: The manufacturing of rimless spectacles comprises manufacturing (S1) two lens blanks of a plastic material, applying a coating to the front side and the rear side of the lens blanks, machining the lens blanks in such way that the two lenses having a desired lens shape are obtained, manufacturing the two lugs, manufacturing the bridge, determining the mounting positions for the fasteners of the lugs and the bridge on the front side/the rear side of the lenses, and removing the coating at the mounting positions to form joining surfaces at the lenses. The manufacturing of rimless spectacles comprises manufacturing two lens blanks of a plastic material, applying a coating to the front side and the rear side of the lens blanks, machining the lens blanks in such way that the two lenses having a desired lens shape are obtained, manufacturing the two lugs, manufacturing the bridge, determining the mounting positions for the fasteners of the lugs and the bridge on the front side/the rear side of the lenses, and removing the coating at the mounting positions to form joining surfaces at the lenses, and adhesively bonding the fasteners of the lugs and the bridge to the front side and/or the rear side of the lenses at the mounting positions. The rimless spectacles comprise two lenses, a bridge disposed between the two lenses for connecting the two lenses to each other, two lugs each of which is connected to one of the two lenses at an edge area of the lens facing away from the bridge, and two sides each of which is hingedly connected to one of the two lugs in which each lug includes a fastener having a joining surface for connecting the lug to either of the two lenses. The bridge includes two fasteners having a joining surface for connecting the bridge to the two lenses. The applied coating comprises a hard layer, a dirt-repelling layer, an anti-reflection layer or a reflective layer. The coating is removed up to the entire thickness of the coating, at the mounting positions. For forming the joining surfaces at the lenses, the coating is removed at the mounting positions in an area of the front side and/or the rear side of the respective lens, which corresponds to shape and dimensions to the joining surface of the respective fastener to be adhesively bonded. The coating is removed by grinding or milling and using a face grinding tool, which performs a high-frequency rotation or reciprocating movement. The coating is removed by abrasive-blasting abrasive particles. The coating is removed by radiation with laser light. The first the respective fastener is arranged at and pressed onto the allocated mounting position and then an adhesive is introduced in a dosed amount between the joining surfaces provided at the lens and at the fastener. For a respective one of the fasteners, a mask having an opening whose contour at least partly coincides with the perimeter of the joining surface of the fastener is detachably fixed at the lenses, namely such that the opening of the mask is provided at the mounting position for the fastener and there delimits the joining surface to be formed at the lens. The coating is removed by an abrasive treatment of the front side or the rear side of the lens in the area delimited by the opening of the mask detachably fixed at the lens. The abrasive treatment is performed by milling, grinding and a grinding tool. The grinding tool performs a high-frequency rotation or reciprocating movement at a frequency of 15-40 kHz, preferably 24-30 kHz. The mounting position for the respective fastener is determined at the lens by means of the opening of the mask. The fastener is adhesively bonded to the lens, while the mask is detachably fixed at the lens. The fastener is attached to the lens in the area delimited by the opening of the mask fixed at the lens and is adhesively bonded to the lens in the given position relative to the latter. The adhesive is introduced in a dosed amount between the joining surfaces provided at the lens and at the fastener after having attached the fastener to the lens. The body is manufactured of metal. The joining surface of a respective fastener has a rectangular shape. The joining surface of the respective fastener is roughened and treated with acetone. The lugs and the bridge are made of a body and the fastener or fasteners. The body is manufactured of a material different from that of the fastener or fasteners. The fasteners are manufactured of a flexible plastic material of low hardness. The hardness of the plastic material is 40-60 Shore D. The body and the respective fastener are manufactured separately and are connected to each other by frictional or positive connection. The fastener is connected to the pertinent body by attaching the fastener by an injection-molding process. An independent claim is included for a mask.